The present invention relates to a lens drive apparatus having a function to restrict a permissible range of operation of an operation member for manual operation, which is provided in a lens apparatus, and a lens-operation restricting apparatus therefor.
In a case of using a lens apparatus capable of zooming and focusing in both an electric mode and a manual mode, an operator selects an electric mode and a manual mode with a change lever according to an image-pickup condition. For example, a zooming operation is carried out in the manual mode when quick framework is required, and zoom drive is carried out in the electric mode when smooth framework is required.
In the electric mode, such a system is common, in which an operation ring provided at the outer circumference of the lens apparatus is driven by a motor. Also, there are many cases where mechanical movement ends corresponding to the telephoto end and the wide-angle end are provided at both sides in the operation direction of the operation ring for zooming.
In such a lens apparatus, depending on the image-pickup condition, there are cases where the range in which the operation ring can be operated is intentionally narrowed in comparison with the range between the telephoto end and the wide-angle end. For example, when a dark image is picked up with an F-number lowered at the telephoto area of zooming, if the zooming operation is restricted at the wide-angle side from the telephoto end, it is possible to securely prevent a dark image from being picked up. In addition, if the zooming operation is restricted at the telephoto end side from the wide-angle end, it is possible to prevent peripheral objects, which are not intended objects to be picked up, from being picked up.
A lens drive apparatus having a function to restrict zooming in a specified range when electric drive is employed has been disclosed in Japanese Patent Laid-open No. 2005-18035. Further, a method has been known, in which a lever is provided outside a manual operation ring, and a zooming operation range for manual operations is restricted by adjusting the position of a lever-operation restricting member attached on the main body of a lens apparatus.
However, in the lens drive apparatus disclosed in Japanese Patent Laid-open No. 2005-18035, the zooming drive range is restricted in the electric mode. However, the lens drive apparatus does not have such a function for the manual operation of the operation ring.
Also, in the method to restrict the zooming operation range by using the lever and the lever-operation restricting member, since there are some projections around the operation ring, the projections may reduce the operability of the operation ring. Since the restriction of the zooming operation range is not always carried out in image pickup, the projections may be provided only when necessary. The work of attaching and detaching the lever and the lever-operation restricting member each time is cumbersome.